President Obama greets supporters after speaking during a Democratic campaign fundraiser in Orlando, Fla., on Oct.11. So far he has raised $155 million for both his campaign and for the Democratic National Committee – more than all the Republican candidates have raised, combined.

Washington — President Obama faces an uphill battle for reelection, with unemployment projected to remain high at about 9 percent through 2012 and job approval ratings in the tank.

But as an incumbent president facing no primary challenger, Mr. Obama enjoys one big advantage: fundraising. So far, he has raised $155 million for both his campaign and for the Democratic National Committee (DNC), which will help his reelection effort. That’s way more than all the Republican candidates have raised, combined.

All that money allows the Obama campaign to start organizing now in the key battleground states, renew contacts with the 2008 voters, and recruit volunteers. The Republicans, meanwhile, are still figuring out who their nominee will be.

Obama’s advantage comes not just in the quantity of money he has raised, but in the opportunity for efficiency. Thus, an early emphasis on high-dollar fundraisers, because each one is a three-fer: In one fell swoop, Obama is pulling in cash for his opponent-free primary season, the general election, and the DNC. If a donor maxes out on all three, that’s $35,800.

“When you’re president, you don’t have time to do two fundraisers a day,” says Anthony Corrado, an expert on campaign finance at Colby College in Waterville, Maine. “[The big fundraisers] allow them to be very efficient with the principals’ time – not just the president, but also the first lady and vice president.”

Another reason to hit the high rollers early: The $30,800 donation limit to the DNC is annual. The Democrats want their big donors to give this year, so they can ask for another $30,800 next year.

For other reasons, small donors are also critical. We don’t see a lot of press releases about the high-dollar events, but plenty of hoopla about how many folks have gone online and sent in even a few bucks.

The Obama campaign home page has a big ticker at the top counting the number of donors. On Monday, the campaign was so excited about reaching its one-millionth donor that press secretary Ben Label sent out a screen shot of the ticker close to 1,000,000 and then another one when it was at exactly 1,000,000.

Last Thursday, in an e-mail to supporters, Obama campaign manager Jim Messina highlighted the number of people who donated in the third quarter of this year – a record 606,027 – before getting to the grand total of money raised, $70 million to the campaign and DNC. Those who donated made 766,000 donations, with 98 percent of them at $250 or less. The average donation was $56.

“That support translates directly to what we can do on the ground,” Mr. Messina writes. “In the past three months we’ve grown our organizing staff by 50 percent, and opened up three new field offices every week. Thousands of volunteers and organizers made 3 million phone calls and in-person visits to voters.”

Donations from the financial services sector present a mixed picture for Obama and the Democrats. The president has raised $15.6 million from employees of that industry, according to an analysis by the Washington Post of data from the Center for Responsive Politics. But some $12 million went to the DNC.

In a head-to-head matchup against leading Republican candidate Mitt Romney, a founder of the private-equity firm Bain Capital, Obama doesn’t fare too well in financial-sector donations. The president has raised just $3.9 million, versus $7.5 million for Romney, the Post reports.

Still, Obama and the DNC have had some success in raising money on Wall Street. One-third of the president’s top 40 fundraisers come from the world of finance, including former New Jersey Gov. Jon Corzine of MF Global, hedge-fund manager Orin Kramer, and UBS executive Robert Wolf, according to the Post.

But the president isn’t exactly advertising the Wall Street support he does have, as he strikes a populist tone in speeches and tells reporters he understands the frustration expressed by the Occupy Wall Street movement.

In the end, Obama’s healthy fundraising numbers – so far, $89 million for his campaign and $66 million for the DNC – don’t tell us much about how he will do on Election Day, Nov. 6, 2012.

“What it shows you is that he retains a loyal base of support,” says Mr. Corrado. “He’s going to amass the sums needed to be financially competitive with whoever the GOP nominee is. But the real question is going to be whether the investment he’s making now in organizing and campaigning is going to be enough to overcome general perceptions about the state of the economy.”